An improved spinal injury parameter model for underbody impulsive loading scenarios

Area of Science:

• Biomechanics
• Spinal Injury Research
• Occupant Safety

Background:

• Underbody blast events cause severe thoracolumbar spine injuries.
• The current Dynamic Response Index (DRI) underpredicts injury risk due to limitations in modeling spinal posture and bending loads.

Purpose of the Study:

• To develop a novel lumped full spine model for simulating spinal responses under different postures.
• To propose a new injury parameter that accounts for axial and rotary forces, addressing limitations of the DRI.

Main Methods:

• Formulated a lumped full spine model with three degrees of freedom per vertebra (axial, shear, rotary motion).
• Utilized inverse parameter identification with eigenfrequency matching to obtain model data.
• Developed a new injury parameter based on vertebral compression from axial and rotary springs.

Main Results:

• The model accurately predicted vertebral motions across various spinal postures.
• The proposed injury parameter accounts for wedge compression and burst fractures.
• The new model demonstrates improved potential for predicting injury compared to the DRI.

Conclusions:

• The developed spine model offers a more comprehensive approach to assessing underbody blast injury risks.
• This research provides a foundation for improved occupant safety systems in vehicles and aircraft.
• The novel injury parameter enhances the understanding of spinal trauma mechanisms.